Railway signaling apparatus



Patented June 1, 1943 RAILWAY SIGNALING APPARATUS George R. Pflasterer, Greenville, Pa., assignor to The Union Switch & Signal Company, Swissvale, Pa., a corporation of Pennsylvania Original application February 23, 1939, Serial No.

257,929. Divided and this application December 13, 1940, Serial No. 369,928

9 Claims.

Myinvention relates to railway signaling apparatus, and it has particular reference to the provision of novel and improved apparatus of the type employed in multiple indication railway signal systems of the class wherein unidirectional current supplied to a control circuit is utilized to establish selective control overtrafiic controlling apparatus in accordance with both the polarity and the coded or non-coded character of such current.

This application is a division of my copending application, Serial No. 257,929, filed on February 23, 1939, for Railway signaling apparatus.

An object of my invention is to provide novel and improved electromagnetic relay means particularly useful in systems of the class described.

Another object is to provide improved systems or the class described incorporating novel relay means effective to prevent signal flashes during reversals of current polarity in a control circuit and to detect coded current in such circuit.

A, further object is to provide improved electromagnetic relay structures incorporating means responsive to current value changes in a relay tomaintain an armature in its attracted position during current changes due either to a reversal of current polarity or the supply of coded current to the relay. and also effective to operate an auxiliary armature to an attracted or operated position in response only to coded current inthe relay.

An, additional object is to provide novel and improved railway signaling apparatus.

The abovementioned and other important objects and. characteristic features ofmy invention which will become readily apparent from the following description, are attained in accordance with my invention by utilizing an operating winding of a relay to eitect operation ofa code responsive armature, a polar armature, and a neutral armature operatively connected with a retaining armature. The neutral and polar armatures. of the relay are arranged to be directly operated in response to flux created by current in the operating winding, while the code responsive and retaining armatures are controlled indirectly by the flux due to. current in the operating winding through the medium, of electromagneticv means inductively coupled with the operating winding and. responsive toflux changes due to changesin current value in the operating winding. The retaining armature is arranged to be operated by the electromagnetic means when-- ever a change in flux conditions occurs in the relay due to a reversal of the polarity of energizat-ion ct theoperating' windingor when the supply of current to the opera-ting winding is periodically varied or interrupted; while the code: responsive armature is arranged to be operated by the electromagnetic means whenand only when periodiwhy varied current in the operating winding causes a continuous variation in flux density in the relay.

I shall describe two forms of apparatus embodying my invention, and shall then point out the novel features thereof in claims.

In the accompanying drawing, Fig. 1 is a front elevational view showing diagrammatically a preferred form of an electromagnetic relay embodying my invention. Fig. 2 is a diagrammatic side elevational' view of the relay shown in Fig. 1. Fig. 3 is a diagrammatic view showing a modified form of the relay shown in Fig. l and also embodying my invention. Fig. 4 is a diagrammatic view showing one form of a control circuit adapted to be employed in connection with a relay of the class represented in Fig. 1 or Fig. 3, and also embodying my invention. In each of the several views, similar reference characters have been employed to designate corresponding parts.

Referring first to Figs. 1 and 2, a relay HD embodying my invention asshown comprises a main magnetic structure having two parallel cores 6a and lib connected together at their upper ends by a backstrap 1 and provided at their lower ends with enlarged pole pieces 8a and 8b, respectively. The core Ga carries the usual operating Winding 9a and the core 6b carries the usual operating winding 9b, and these windings are connected together in such manner that when energized, the windings cooperate in circulating aflux in cores 6a and 6?). Two secondary windings 20a. and 20?) disposed respectively on cores 6a and 6b in inductive relationship with windings 9a and 9b, are connected in series in such manner that when electromotive forces are induced therein due to a change in fiux value in cores 6a and 62), such electromotive forces are additive. Thefunction of the two secondary windings 20a and 291) will be pointed out hereinafter.

A first neutral armature N pivotally pinned at [5 to a nonmagnet bracket (not shown) suspended from pole pieces 8a and 8b, is disposed in magnetic relationship with such pole pieces so as to be attracted or actuated to an upper or picked-up position in response to flux due to current in operating windings 9a and 9b. In accordance with the usual practice, armature N is adapted to close the usual front and back contacts (not shown in Figs. 1 and 2).

Associated with the main magnetic structure of relay HD is a constantly magnetized core Ill here shown as a permanent magnet, the upper end of which engages the underside of an extension la of the backstrap l, and the lower end of which is provided with a bifurcated pole pieces I l. Pivoted at l2, between the bifurcations of the pole iece H, is a polar armature P. The pole pieces 8a and 8b of the main magnetic structure are provided with integral extensions Ito and l3b,

respectively, the pole pieces of which overlie the opposite ends of the armature P. It is apparent that armature P will swing toward one or the other of these extensions depending upon the polarity of the current supplied to operating windings 9a and 9b, stops Ma and Nb being attached to extensions lta and Nb, representively, to prevent the armature from actually engaging the extensions. The armature P is adapted, in accordance with the usual custom, to close polar contacts when swung in one direction and to open such contacts and close other polar contacts when swung to the other position, and the parts of the relay are so arranged and proportioned that polar. armature P is retained at the position to which it is swung until the polarity of current operating the armature to that position is reversed.

Relay HD further comprises an auxiliary magnetic structure having two parallel cores 16a and IE1) connected together at their upper ends by a backstrap l1, and provided at their lower ends with pole pieces la and I319, respectively. The core Ilia is provided with an auxiliary winding 19a and the corev 16b is provided with a similar auxiliary winding lSbL Auxiliary windings iiia i and ISlb are inductively coupled with operating windings 9a and 91) through the medium of the previously mentioned secondary windings 20a and 20b, A full-wave rectifier 2| is interposed in the connection of auxiliary windings Na and I9?) to secondary windings 26a and 20b, and it follows that unidirectional current of a given relative polarity will be supplied to windings Na and I5?) regardless of the polarity of current caused to be induced in windings 28a and 2% due to a change in flux in cores 6a and Eb. That is to say, current of one relative polarity is induced in wind ings 20a and 20b during the growth of flux in cores-6a and 627 due to an increase in current value in windings 9a and 9b, and current of the opposite relative polarity is induced in windings 20a and 261) during the decay of flux due to a decrease in currentvalue in windings 8a and 912. It is readily apparent, therefore, that due to the rectifyingaction of rectifier 2|, windings Mia and 19b are supplied with current of a given relative polarity whenever any change of flux occurs in cores 6a and 617. When, however, there isa steady state condition of flux in cores Ea and 6b dueto the supply of steady or non-coded unidirectional current to windings 9a and 9b, the auxiary windings Mia. and I97), are, of course deenergized.

A second neutral armature XN is disposed beneath pole pieces l8a and l8b, in a manner such as to be magnetically attracted to a predetermined or upper position by the flux created in such pole pieces whenever windings l9a and I921 are energized. The armature XN as shown by a dotted line is mechanically connected with armature N provided for the main magnetic structure,- the connection being preferably established by means of a rigid strip of any suitable nonmagnetic material. The armature XN is preferably proportioned so that, when once operated to its upper attracted position, the armature will be held at its upper position in response to flux created by current supplied to auxiliary windings l9a and'lfib from secondary windings 29a and 20b when the polarity of-current in operating windings 9a and 9b is reversed. Preferably, the

auxiliary magnetic structure is so located with respect to the pivotpoint ll) of armature N that when auxiliary windings l9a and 191) are energized by current caused to be induced in windings 2041 and 2% upon reversing thepolarity of current in operating windings 9a and 9b, armature XN is retained in its upper position to retain armature N also at its upper position during the interval of time required for a reversal of current polarity in operating windings 9a and 9b.

A third neutral armature NC also is disposed beneath pole pieces [8a and [81) so as to be magnetically attracted to a predetermined or upper position by flux created in such pole pieces due to current in windings [9a and I91). Armature NC is preferably soproportioned as to be attracted to its upper position only when windings l9a and I91) are continuously energized by unidirectional current. That is to say, armature NC is responsive only to the greater flux density created by windings Ida and 19b in response to current caused to be continuously induced in secondary windings 20a and 20?) due to periodically interrupting the supply of current to windings 9a and 9b. Armature NC therefore functions to detect the supply of coded current to windings 9a and With the relay constructed in the manner just described, the relay will operate as follows: When operating windings 9a and so are supplied with continuous or non-coded current of a polarity which I shall term positive polarity, polar armature P is swung to its left-hand position, that is, the left-hand end as viewed in Fig. 1, of armature P is attracted to pole extension 13d, and neutral armature N is attracted to its upper position. In this condition of the apparatus, armature XN is likewise raised to its upper position because of its mechanical connection with armature N. If, now, with the apparatus in the condition just described, the polarity of current is reversed so that windings 9a and19b become energized by current which I shall term negative polarity, polar armature P is caused to operate to its right-hand position, that is, the position shown in! Fig. l. The current caused to be induced in windings 28a and 20?) by the change in flux in the main magnetic structure when the current supplied to windings so and 9b is reversed, momentarily energizes windings |9a and i917, with the result that armature XN is held in its upper position during the interval'of time required for the current of negative polarity to build up to a value effective with periodically interrupted or coded current of negative polarity, and the constantly changing flux in the main magnetic structure induces current in secondary windings 20a and 20h.

This induced current is supplied through rectifier 21 to auxiliary windings 19a and l9b as unidirectional current and it creates magnetic flux which actuates armatures XN and'NC to their respective upper positions. Armature N is also held in its upper attracted position since it is not only held attracted by flux due'to current in windings 9a and 5b but it is also mechanically connected with armature XN which is held attracted by flux due to current in windings I So and 19b. In the event that the periodically interrupted current supplied to operposition and armatures N, XN and NC are retained in their upper positions since the constantly changing fiux in the main magnetic structure induces current in secondary windings 29a and 2017, as explained hereinbefore.

From the foregoing, it is apparent that I have provided a relay selectively responsive to each of four different forms of unidirectional current which may be supplied to the relay. That is to say, neutral armature N is attracted to its upper position in response to each of the four forms of current, and is retained at its upper position whenever the polarity of current supplied to the relay is reversed; neutral armature NC is attracted to its upper position in response to coded or periodically interrupted current of either polarity; and polar armature P is attracted to its left-hand or to its right-hand position in response to the polarity of current energizing the relay regardless of the coded or noncoded character of such current.

Fig. 3 illustrates diagrammatically a modified form of the relay shown in Figs. 1 and 2. Referring now to Fig. 3, the apparatus of Figs. 1 and 2 is modified by the provision of transformer 22, which replaces secondary coils 20a and 20b shown in Figs. 1 and 2. Transformer 22 is provided with a primary winding 23 connected in series with operating windings 9a and 9b, and with a secondary winding 24 connected through rectifier 2! with auxiliary windings 19a and 19b.

It is readily apparent that transformer 22 of Fig. 3 will function in a manner similar to secondary coils 20a and Zllb of Figs. 1 and 2 for supplying induced current to auxiliary windings IM and I!!!) so that the relay shown in Fig. 3 operates similarly to the relay shown in Figs. 1 and 2.

An advantage of an electromagnetic relay constructed in the manner shown in Figs. 1 and 2 is that such relay provides means operated by changes in flux in the relay for controlling a neutral armature arranged to detect energization of the relay and a code responsive member or armature arranged to detect energization of the relay by coded or periodically varied current. The inductive coupling of the operating winding of a relay to a secondary winding mounted on the relay core, and utilizing means responsive to current induced in the secondary winding to effect operation of an armature arranged to detect the supply of coded current to the relay, provides astructural arrangement having im proved operating characteristics over arrangements heretofore proposed in that the energization of the relay is available to control the neutral and polar armatures of the relay and changes in the energization of the relay are utilized to control the operation of the neutral armature and an auxiliary member or armature arranged to detect the supply of coded current to the relay. As a result, therefore, a system incorporating such a relay arrangement in a control circuit is operative in response to an energy level in the control circuit substantially lower than. the energization heretofore required in proposed systems, since the relay winding functions not only as an operating winding to operate armatures detecting the polarity and energization of the circuit but also functions as a primary winding of a code detecting transformer to effect operation of an armature or member detecting coded current in the circuit. In addition, the particular structural arrangement shown in Figs. 1 and 2 provides a unitary structure wherein a code responsive, a polar, and a neutral armature operatively connected to a retaining armature, are selectively controlled in accordance with the polarity and the coded or non-coded character of the current energizing the relay, thereby resulting in a marked decrease in the cost, space requirements, and number of structures required in signal systems arranged to respond selectively to both the polarity and the coded and non-coded character of unidirectional current supplied to a control circuit.

Relays constructed in accordance with my invention are particularly well adapted for use in multiple indication railway signal systems of the above described class and I have represented in Fig. 4 a relay HD constructed in accordance with my invention and incorporated into a multiple indication wayside signal system governing trafiic on a stretch of railway track over which trafiic normally operates in the single direction indicated by an arrow in the drawing. The stretch of track is divided by insulated joints 2 into a plurality of successive adjoining track sections, of which only the adjacent portions of two of such sections and the control apparatus associated therewith are illustrated in the drawing.

Referring now to Fig. 4. the control apparatus associated with the stretch at H comprises a track relay TR5, connected to the rails adjacent the entrance end of the section and arranged to respond to current supplied to the other end of the section (not shown) from a suitable source of current such as a battery corresponding to battery 3 shown connected to the rails at the exit end of the section next in the rear of the section associated with relay TRS; a control relay HD5 constructed in accordance with my invention in a manner explained hereinbefore and connected to a control circuit governed by relay TF5 and comprising conductors 4 and 5 adapted to be supplied with either coded or non-coded unidirectional current of one relative polarity or the other; a signal S5 governing traffic on the stretch and selectively controlled by relay HD5; and an auxiliary pole changing relay P05 and a code transmitter or coder GT5 controlled respectively by relay HD5 and in turn controlling the energization of the control circuit of section next in the rear of the section associated with signal S5. The coder GT5 may be of any suitable type and as shown comprises a winding which when energized operates contacts 25 and 2S alternately into and out of engagement with their associated back contact points. Signal S5 likewise may be of any suitable form but as shown comprises two signal units U and L each comprising a semaphore signal mechanism having an arm capable of assuming a horizontal or stop. a 45 or caution, and a vertical or clear position. These semaphore units are arranged as is the customary practice to be controlled by two separate energizing or control circuits in such mannor that a unit is condition ed to operate its associated arm to its 45 position when unit is energized over one circuit, the associated arm is operated to the vertical position. when the asso ciated unit is energized over both circuits. and when the unit is deenergized, the associated arm is operated to its horizontal position.

When the section associated with signal S5 is occupied by a train W, as represented in Fig. 4,

relay TR5 releases and its front contacts 21 and. 28 open to interrupt the control circuit of and deenergize relay HD5. Neutral armature N and code responsive armature NC of relay I-lD5 accordingly occupy their respective released positions, while polar armature P occupies its last operated position, here assumed to be its normal or left-hand position, as viewed in Fig. 4. Under the above assumed conditions, both units U and L of signal S5 are deenergized and the associated semaphore arms are in their respective stop positions, while relay PC5 is released and coder C'T5 is deenergized and inactive. The control circuit of the section next in the rear is conditioned to be supplied through back contacts 34 and 35 of relay PC5 with non-coded unidirectional current of what I shall term normal polarity supplied to wires 4 and 5 from a suitable source of current, such as a battery not shown, but having its opposite terminals designated by the reference characters B and C.

When the section associated with signal S5 is u occupie and non-coded unidirectional current of normal polarity is supplied to the associated control circuit by suitable apparatus (not shown but corresponding to the apparatus represented in Fig. 4 at H), neutral armature N of relay HD5 is operated to its upper or attracted position and polar armature P is retained at its normal position, while code responsive armature NC is retained at its released position. An obvious energizing circuit for unit U of signal S5 is completed at front contact 36 of armature N of relay HD5, and the arm of unit U accordingly is operated to its 45 position. Front contacts 39 and. 40 of armature N are also closed to reverse the polarity of the current supplied to wires 4 and 5 of the control circuit of the section next in the rear, as is readily apparent from an inspection of the drawing. Unit L of signal S5, relay PC5, and coder CT5 are, however, deenergized.

When relay HD5 is supplied with non-coded current of reverse polarity, its polar armature P is operated to its reverse or right-hand position, neutral armature N is maintained in its attracted position, and code responsive armature NC remains released. Unit U of signal S5 is energized over its previously mentioned circuit including front contact 36 of neutral armature N, and unit L of signal S5 becomes energized over a circuit extending from terminal B through front contact 44 of neutral armature N, reverse polar contact 42-45 of polar armature P, wire 30, and unit L of signal S5 to terminal C, with ,l

the result that both units U and L of signal S5 operate their respective arms to the 45 or caution position. Coder CT5 also becomes enersized over a circuit extending from terminal B through front contact 46 of neutral armature N, reverse polar contact 43-41 of polar armature P and the winding of coder GT5 to terminal C, and the control circuit of the section next in the rear is supplied with coded current of reverse polarity.

In the event that relay HD5 is supplied with coded current of reverse polarity, neutral armature N and code responsive armature NC are both operated to their respective upper or attracted positions, while armature P is retained at its reverse position. Under such assumed conditions, unit U of signal S5 is energized over its previously mentioned circuit including front contact 36 of neutral armature N and operates its arm to the {1 position, while the arm of unit L is operated to its vertical position in response to the energization of that unit over two circuits the first of which corresponds to the circuit previously traced for unit L and the second of which extends from terminal B through front contact 44 of armature N of relay I-IDS, reverse polar contact 4245 of polar armature P, front contact 48 of code responsive armature NC, wire 3| and unit L to terminal C. Coder GT5 is energized over its previously traced circuit including front contact 46 of neutral armature N and reverse polar contact 43-41 of polar armature P of relay I-ID5, and pole changing relay PC5 also is energized over a circuit extending from terminal B through front contact 49 of neutral armature N. front contact 50 of code responsive armature NC and the winding of relay PC5 to terminal C, with the result that relay PC5 is energized to close its front contacts 5| and 52 to condition the apparatus at H to supply coded current of normal polarity to the control circuit of the section next in the rear.

When relay I-ID5 is supplied with coded current of normal polarity, neutral armature N and code responsive armature NC are both operated to their attracted positions, and polar armature P is operated to its normal or left-hand position. Under such assumed conditions, unit U of signal S5 is energized over a first circuit including front contact 36 of armature N, and also over a second circuitextending from terminal B through front contact 36 of armature N, normal polar contact 4I--53 of polar armature P, front contact 54 of code responsive armature NC and unit U of signal S5 to terminal C, hence the arm of unit U is operated to its vertical or position, while unit L of signal S5 is deenergized and its arm occupies kits horizontal position. Pole changing relay PC5 is energized over its previously traced circuit, and coder 0T5 is energized over a circuit extending from terminal B through front contact 46 of armature N, normal polar contact 43--55 of polar armature P, front contact 56 of code responsive armature NC and 0 the winding of coder GT5 to terminal C, and as a result the control circuit of the section next in the rear is supplied with coded current of normal polarity.

From the foregoing description, it is apparent that a relay embodying my invention and selectively controlling a plurality of armatures including a neutral, a polar and a code responsive armature, may be utilized to establish selective control over a multiple indication railway trafllc controlling signal in accordance with the polarity and the coded or non-coded character of the current supplied to the relay. It is also apparent that when the polarity of current supplied to a relay embodying my invention is reversed, the neutral armature controlled thereby is retained in its energized or attracted posit-ion, thereby preventing the neutral armature from releasing to open the front contact controlled thereby. It follows that, inasmuch as it is customary to control a signal to its most restrictive indication when the associated signal control relay is deenergized, a signal controlled by a relay embodying my invention is'not subjected to momentary flashings of such restrictive indications when the polarity of current in the control circuit is reversed.

Although I have herein shown and described only two forms of railway signaling apparatus embodying myinvention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. In combination, a relay having an operating winding, a neutral armature operated by said winding to detect energization of the relay and a polar armature operated by said winding to detect the polarity of energization of said relay, retaining means active at times to retain said neutral armature in its energized, picked-up position, electromagnetic means inductively coupled with said operating winding and responsive to changes in fiux conditions in said relay for rendering said retaining means active when periodically interrupted or coded current is supplied to the relay and when the polarity of energization of the relay is reversed, and a code detecting member controlled by said electromagnetic means to an operated position when and only when periodically interrupted or coded current is supplied to said relay.

2. In a relay having a neutral armature, a polar armature and a code responsive armature, an operating winding for operating said neutral and polar armatures in response to fiux created by current in said winding, retaining means active at times to retain said neutral armature in its operated position, and electromagnetic means inductively coupled with said operating winding and responsive to changes in flux conditions in said winding for rendering said retaining means active and for at times operating said code responsive armature.

3. A relay having armatures selectively responsive to the polarity and the coded or non-coded character of current supplied to the relay, comprising a first magnetic structure provided with operating windings, a neutral armature and a polar armature operated respectively by flux due to current in said operating windings, an independent magnetic structure having windings inductively coupled with said operating windings, and a code responsive armature operated solely by flux due to a continuous supply of current to said last-mentioned windings.

l. In a relay having a neutral armature responsive indiscriminately to energization of the relay, a polar armature responsive selectively to the polarity of energization, and another armature responsive only to periodically interrupted or coded energization of the relay, the combination of an operating winding mounted on a magnetic structure, a neutral armature and a polar armature disposed in magnetic relationship with said magnetic structure and operated by flux due to current in said operating winding, an independent magnetic structure, a rectifier, an auxiliary winding mounted on said independent structure and connected through said rectifier to a secondary winding disposed on said first magnetic structure, and another armature disposed in magnetic relationship with said independent structure and responsive only to flux due to current caused to be continuously supplied to said auxiliary winding from said secondary winding. when coded current is supplied to said operating winding.

5. In a relay having a neutral armature responsive indiscriminately to energization of the relay, a polar armature responsive selectively to the polarity of energization, and another armature responsive only to periodically interrupted or coded energization of the relay, the combination of an operating winding mounted on a magnetic structure, a neutral armature and a polar armature disposed in magnetic relationship with said magnetic structure and operated by flux due to current in said operating winding, an independent magnetic structure, a rectifier, an auxiliary winding mounted on said independent structure and connected through said rectifier to a secondary winding disposed on said first magnetic structure, a retaining armature disposed in magnetic relationship with said independent structure and mechanically connected to said neutral armature, and another armature disposed in magnetic relationship with said independent structure and responsive only to flux due to current caused to be continuously supplied to said auxiliary winding from said secondary winding when coded current is supplied to said operating winding.

6. In a relay having a main magnetic structure provided with operating and secondary windings, for operating a neutral armature in response to flux due to current in said operating winding, a rectifier, an independent magnetic structure having energizing windings connected through said rectifier to said secondary winding, and an armature operated solely by fiux due to current caused to be continuously supplied to said energizing windings from said secondary windings when and only when coded or periodically interrupted current is supplied to said operating windings.

7. In combination, a relay having operating and secondary windings mounted on a core structure for operating an armature in response to flux created by curent in said operating winding, a rectifier, an independent magnetic structure having energizing windings connected through said rectifier to said secondary windings, and another armature independent of said first armature and operated solely by flux created by current caused to be supplied to said energizing windings from said secondary windings when and only when coded current is supplied to said operating windings.

8. A relay comprising two magnetic structures one provided with an operating winding and a secondary winding and the other provided with an energizing winding connected through rectifying means to said secondary winding, a first armature member controlled jointly by flux due to currents in said operating winding and in said energizing winding, a polar armature member responsive to the polarity of flux due to current in said operating winding, and another armature member operated solely by flux due to current continuously supplied to said energizing winding.

9. A relay comprising two magnetic structures one provided with an operating winding and a secondary winding and the other provided with an energizing winding connected through rectifying means to said secondary winding, a first armature member controlled jointly by flux due to currents in said operating winding and in said energizing winding. and another armature member independent of said first armature member and operated solely by fiux due to current continuously supplied to said energizing winding.

GEORGE R. PFLASTERER. 

